Mamey Sapote Seed Oil (Pouteria Sapota). Potential, Composition, Fractionation and Thermal Behavior

GRASAS Y ACEITES 66 (1) January–March 2015, e056 ISSN-L: 0017-3495 doi: http://dx.doi.org/10.3989/gya.0691141

Mamey sapote seed oil (Pouteria sapota). Potential, composition, fractionation and thermal behavior

J.A. Solís-Fuentes1,*, R.C. Ayala-Tirado1, A.D. Fernández-Suárez1, and M.C. Durán-de-Bazúa,2,* 1Instituto de Ciencias Básicas, Universidad Veracruzana. Av. Dos Vistas s/n carretera Xalapa-Las Trancas, 91000 Xalapa, Ver., México 2Facultad de Química, UNAM. Conjunto “E”, Labs E301-E302-E303, Ciudad Universitaria, 04510 México, D.F. *Corresponding authors: [email protected]; [email protected]

Submitted: 05 June 2014; Accepted: 10 September 2014

SUMMARY: The chemical composition of the waste from mamey sapote (Pouteria sapota) and its oil extracted from the seed (MSSO) of ripe and unripe fruits, was studied. The MSSO from ripe fruits was dry-fractionated, and the thermal and phase behaviors of its fractions and their mixtures with other known natural fats were analyzed. The main components of the mamey peel and the seed were crude fiber (81.32%) and fat (44.41% db), respectively. The seed oil contained oleic, stearic, palmitic and linoleic as its main fatty acids. The MSSO showed a simple thermal behavior with a broad fusion range and four maximum temperature peaks. The solid fractions showed maximum melting peaks at higher temperatures than the residual liquid. The MSSO solid fractions showed a potential for use as constituents in mixtures with other natural fats, such as cocoa butter or mango seed fat.

KEYWORDS: DSC; Mamey sapote; Oil fractionation; Pouteria sapota; Seed oil RESUMEN: Aceite de semilla de Zapote Mamey (Pouteria sapota). Potencialidad, composición, fraccionamiento y comportamiento térmico. Se estudió la composición de los residuos del zapote mamey (Pouteria sapota) y del aceite extraído de la semilla (ASZM) de frutos maduros e inmaduros. El ASZM de frutos maduros fue frac- cionado en seco y se analizó la conducta térmica y de fase de las fracciones y mezclas de éstas con otras grasas naturales conocidas. Los principales componentes de la cáscara y de la semilla fueron fibra cruda (81.32% bs) y grasa (44.41% bs), respectivamente. Los principales ácidos grasos del ASZM fueron: oleico, esteárico, palmítico y linoleico y mostró una conducta térmica simple con un intervalo de fusión amplio y cuatro máximos de temperatura. Las fracciones sólidas obtenidas presentaron máximos de fusión a temperaturas más altas que la fracción líquida residual. Las fracciones sólidas del ASZM mostraron potencialidad para usarse como consti- tuyente en mezclas con la manteca de cacao y la grasa de la semilla de mango.

PALABRAS CLAVE: Aceite de semilla; DSC; Fraccionamiento de aceites; Pouteria sapota; Zapote mamey

Citation/Cómo citar este artículo: Solís-Fuentes JA, Ayala-Tirado RC, Fernández-Suárez AD, Durán-de-Bazúa, MC. 2015. Mamey sapote seed oil (Pouteria sapota). Potential, composition, fractionation and thermal behavior. Grasas Aceites 66 (1): e056. doi: http://dx.doi.org/10.3989/gya.0691141.

1. INTRODUCTION local contexts, the cultivation, use and consumption of indigenous plant species in detriment of The effects of predominating exogenous cul- the natural biodiversity. The case of P. sapota can tural patterns promoted by the globalization of exemplify the great potential of many various spe- the world economy have often discouraged, in cies from Mesoamerica to support its current and 2 • J.A. Solís-Fuentes, R.C. Ayala-Tirado, A.D. Fernández-Suárez and M.C. Durán-de-Bazúa future populations (Solís-Fuentes and Durán-de- the mamey sapote (>40% db) has motivated some Bazúa, 2002). research designed to understand the oil extraction The extensive family Sapotaceae is divided into process, its chemical composition, physicochemical five tribes with 53 genera and about 1250 species characteristics, and some other studies regarding its distributed worldwide, mainly in the tropical and potential applications. subtropical regions of Asia and Mesoamerica. The Oil extraction through the mechanical expres- Pouteria genus comprises 325 species (Triono et al., sion of the mamey seed was studied by Cravotto 2007). Many of them produce quality wood and edi- et al., (2011). They found that it is possible to obtain ble fruits of high economic value; in addition, sev- a high quality oil, free of contaminants and sol- eral of these species have been used in traditional vent residues, with a yield of up to 18% of the dry medicine for various purposes (Silva et al., 2009). mass of the seed. Alvarez-Reyes et al., (2001) and Mamey sapote (tzapotl: fruit with bone and Solis-Fuentes et al., (2001) studied the process of mama: hands, in Nahuatl language; Simeon, 2002; mass transfer during the extraction of seed oil with Nava-Cruz and Ricker, 2004) is, in Mexico and organic solvents and found that the process was some parts of Central America, one of the ver- affected by the particle size, the extraction time and nacular names given to the fruit of P. sapota (Jacq.) the relationship of seed mass/solvent volume. Under H.E. Moore & Stearn. It is an endemic plant grow- certain conditions, it was possible to extract practi- ing in the warm climates of Mesoamerica, currently cally all of the oil contained in the sapote almonds. located, also, in some regions of North America, The apparent diffusivity coefficient of the oil from Asia and Africa. the unbroken seed cells was 6.9 × 10−13 at 25 °C, a The mamey sapote is a rounded, oval or elliptical value whose magnitude is similar to that reported fruit from 7.5 to 22.8 cm long and weighing between in the literature for other oilseeds, like peanuts and 0.227 and 2.3 kg, with a rough and firm peel that soybeans (Krasuk et al., 1967). resembles dark brown leather or bark. The fruit Laiz-Saldaña et al. (2009), showed the possibility pulp has a sweet flavor like pumpkin and a color of using mamey seed oil for biodiesel production, from salmon-pink to dark red. It has a long stone highlighting a favorable outlook from economic and which is spindle-shaped, hard and bright brown. technical points of view, since the mamey seed is still The kernel or seed is oily, bitter and with a char- a residue. Nonetheless it has high oil content with a acteristic odor like almonds (Morera, 1994). The predominantly non-saturated fatty acids. edible part of mamey its pulp is mainly consumed Today mamey oil is being reassessed beyond arti- fresh, but is also used for making jam, ice cream, sanal applications and has been analyzed in greater sauces and other regional food products. detail, for example, it is acquiring an interesting posi- The mamey fruit is highly prized for its flavor tion as a source of triterpene alcohols, whose prop- and its acceptance is growing on the world market. erties are interesting for applications in cosmetics (it However, there are few scientific reports on the is commonly considered to be effective in skin care chemical composition, physical properties and and its healing, to improve tolerance to UV radia- nutritional characteristics of its edible portion. tion, etc.) and pharmacology (anti-inflammatory There is limited knowledge too, of other parts of capacities, erythema and sunburn treatments, etc.) the fruit and the plant, despite its use and impor- (Parodi Nutra, 2013; De la Llata-Romero, 2013). tance in some Mesoamerican indigenous cultures. It One aspect, sparsely addressed, is the potential is known, for example, that in some towns, people use of this oil in the food sector where, because of its still cook the seeds in water and then roast and mix characteristics, it could be an interesting source of them with cocoa for preparing chocolate. In Central vegetable fats with specific phase properties, obtained America, the almonds are finely milled for making by means of oil fractionation or oil mixing processes special confectionaries. The kernel or almond of (Timms, 1985, 2005, 2006). This issue is important this seed has served as a source of perfume essences. in the ongoing efforts to replace fats that currently Traditional medicine recognizes that it has beneficial are produced through industrial processing with the effects on coronary, rheumatic and kidney problems. partial hydrogenation of oils; this results in fats with The mamey seed oil has been used in the artisanal high contents of trans fatty acids, compounds with manufacturing of soap, ointments for the skin, hair serious objections from nutritional and public health conditioners and as sedative products for disorders points of view (Precht and Molkentin, 1995; Khosla of the eyes and ears (Morton, 1987; Morera, 1994). and Sundram, 1996; Tarrago-Trani et al., 2006). In general, it is known that the seeds of the fruits, The fractionation of vegetable oils is a process because of their biological functions, are rich in that, in recent decades, has been strongly reval- nutrients and are a source of vegetable fats, starches, ued due to the fact that it can produce vegetable proteins, and many compounds which are useful fats from oils without severe thermal treatments, as raw or supplementary materials for elaborating thus achieving more natural and healthy products other products in the food, pharmaceutical and cos- (Tarrago-Trani et al., 2006). The dry fractionation metics industries. The high oil content of the seed of of vegetable oils has significant advantages from

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141 Mamey sapote seed oil (Pouteria sapota). Potential, composition, fractionation and thermal behavior • 3 an economic and environmental protection per- the resulting micelle in a rotary laboratory (Büchi spective compared to the wet fractionation of oils RE 111) at reduced pressure. with organic solvents (Timms, 2006). The lipid fraction was stored in a container pro- This paper summarizes some results of an investi- tected from light under refrigerated conditions until gation concerning the fruit of mamey sapote, mainly processing and/or analysis. of its traditionally non-food waste portions, in order The obtained oil was purified by an adaptation to further their comprehensive utilization through of the Wesson method (Mehlenbacher, 1970). In greater knowledge of their characteristics and po- this procedure, the oil was dissolved in petroleum tentiality as a source of raw materials. The aim of ether (1:5 mass/volume) and 1 mL of a 14% potas- this study was to estimate the possibility of obtain- sium hydroxide solution was added to each gram of ing oils from residues of mamey sapote in its mature oil, with vigorous agitation; subsequently, 50% ethyl and immature states, to study the composition of the alcohol was added at 1:2.5 (mass/volume) based on oil extracted and purified from the seed and to carry the mass of oil, with agitation and then resting, until out the dry fractionation of the oil in order to estab- separation of the phases. The ether layer containing lish its thermal and phase behavior, of great impor- the neutral oil was processed to recover the purified tance for comprehending its potential uses. oil. It was then stored under refrigeration (−5 °C) and protected from light until processing and/or analysis. 2. MATERIALS AND METHODS 2.4. MSSO physicochemical properties 2.1. Sampling and percentage estimate for each component of the fruit The refractive index, saponification value and iodine value of MSSO were measured using official Immature and mature fruits of P. sapota were ran- analysis techniques (Horwitzs, 1995). domly collected from the producing region located in the municipality of Emiliano Zapata in the State 2.5. Fatty acid pattern of MSSO of Veracruz, Mexico. Fruits from each batch were weighed and the anatomical parts of each of them, The oil was converted into the methyl esters cor- peel, pulp, stone, and seed, were removed in order to responding to its fatty acids; then they were sepa- estimate the average percentage of each relative to rated and analyzed through gas chromatography the total mass of the fruit. and mass spectroscopy in accordance with the meth- odologies described by Horwitzs (1995); Bannon 2.2. Chemical and proximal analyses of the peel, pulp et al. (1982) and Hendrikse et al. (1994). and seed of mamey sapote The boron trifluoride method (Horwitzs, 1995) was used for oil esterification. The peel, pulp and seed of the mamey were physi- The analysis of fatty acid methyl esters was car- cally and chemically analyzed in terms of their con- ried out in a Hewlett Packard model 5890 series II tents in moisture, ash, crude fiber, proteins and fats gas chromatograph (Hewlett Packard Co., Palo Alto, by using the official analysis techniques (Horwitzs, CA, USA), coupled to a JEOL SX-102A mass spec- 1995). Lots of pulp and seed were studied in the two trometer with an electron ionization detector. The stages of development considered and character- system had an AT Silar capillary column (Alltech ized further into other relevant components. For the Associates, Inc., Deerfield, IL, USA) 30 m long and pulp, the stage of its physiological development was 0.32 mm internal diameter and 0.25 μm film thick- characterized through titratable acidity (by neutral- ness. A database that contains about 75 000 com- ization with an alkaline solution), reducing sugars pounds supplemented with the internal standards and total sugars (with the Lane and Enyon method), of methyl ester fatty acids (Sigma) was used for the pH (potentiometric method) and tannins (with the identification of compounds. Helium was used at method of Folhin-Denis). The seeds were further a flow of 0.4 mL·min−1 and 38 kPa; the inlet tem- analyzed for their tannin and cyanide contents (with perature was 250 °C and the initial temperature of the Folhin-Denis method and alkali titration) accord- the oven was 100 °C. The temperature program was: ing to official analysis techniques (Horwitzs, 1995). 2 min at 100 °C and increments of 4 °C·min−1 till 180 °C was attained. The mass analyzer operated in 2.3. Extraction and purifi cation of mamey sapote a mass range of 10:450 m/z. seed oil (MSSO) 2.6. Dry fractionation of MSSO The oil was extracted in a Soxhlet apparatus using hexane. The extraction was performed during MSSO fractionation was performed through a periods of 6 hours from dehydrated and milled seeds homogeneous crystallization by applying slow cooling (with about 15% humidity) until the samples were and spontaneous nucleation (O’Brien, 1998; Timms, completely exhausted. The solvent was removed from 2005). The procedure included: a) MSSO heating

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141 4 • J.A. Solís-Fuentes, R.C. Ayala-Tirado, A.D. Fernández-Suárez and M.C. Durán-de-Bazúa

to 90 °C for 10 min; b) controlled cooling for crystal T nuclei formation in a circulation and refrigeration bath ∫ HT() dt (Polyscience Model 911), for which the temperature = T 0 SFI() T T1 was gradually reduced from 30 °C until the appearance ∫ HT() dt of crystalline nuclei (26.5 and 23.8 °C); c) crystalline T 0 aggregates were allowed to grow over a sufficient time period at each temperature for the MSSO to form a sufficient solid fraction; d) the separation of the solid The partial areas of the thermograms were cal- and liquid phases at the established temperatures was culated and correlated with the percent of solids done in a Hettich (Tuttlingen, Germany) refrigerated in the samples, considering that at −60 °C the oil centrifuge, model Universal 32R. The recovered frac- samples were 100% solid. Samples of cocoa butter tions were placed in amber bottles and stored under (CB) and mango seed fat (MSF) and binary mix- refrigeration (−5 °C). tures of MSSO fractions with these natural fats were prepared for the analysis of their thermal behavior 2.7. Thermal behavior of MSSO and its fractions and consistencies through the calculation of their solid-liquid relationships. In each one of the cases, 2.7.1. Melting and crystallization profi les binary mixtures were prepared with the solid fractions recovered from MSSO at 0.25, 0.50,75 and The melting and crystallization profiles of 100% of participation in the blends. MSSO and its fractions were analyzed with a TA Instruments 910 and 2910 Differential Scanning 3. RESULTS AND DISCUSSION Calorimeter (New Castle, DE USA), equipped with a thermal analysis data station (Thermal Analysis 3.1. Morphology of the constituent parts of the 2100). The purge gas was nitrogen at 20 mL·min−1 immature and mature mamey fruits and indium (melting point of 156.6 °C and ΔHf of 28.45 J·g−1) was used for calibration. Samples of The tender (immature) and mature fruits showed 5 to 15 mg were weighed in aluminum capsules with qualitative differences under observation. The imma- a TA Instruments Thermobalance (model 2950) and ture fruit, for example, presented a dark-brown, hard hermetically sealed. An empty sealed capsule of the and gritty epicarp like that of the ripe fruit, but not same type was used as reference. fully differentiated from the pulp (mesocarp), which The DSC temperature program was: was light-brown and greenish in color, with a characteristic odor and an astringent taste. The stone −1 was not well shaped and had a light brown color. 1) Cooling to −60 ° C and heating at 10 °C·min The seed of the tender mamey showed relatively till 90 °C, for registering the profile and the defined tissues and the presence of a weak seed coat enthalpy of melting. (integument) with a higher moisture content than 2) Heating to 90 °C for 10 min and cooling at −1 the mature one. 10°C·min till −60 °C, for registering the profile The ripe sapote fruit presented a distinct shell of and the enthalpy of crystallization. mesocarp. The pulp was orange-red in color with a characteristic taste and odor. It had a well-defined To demonstrate the effect of thermal history and stone, dark brown in color with a white ventral line, polymorphic effects, some samples of the fractions and a well-defined seed showing the presence of obtained were tempered prior to the DSC analysis integument; seed tissues were firmer than the imma- by heating at 90 °C for 5 min and cooling to room ture ones, and it had a lower water content than that temperature (between 22 and 24 °C); then they were of the immature fruit. held at that temperature for 24 hours and, finally stored for 15 days at 5 °C. 3.2. Chemical composition of the mamey peel, pulp and seed 2.7.2. Fat solid-liquid relationships of MSSO and its fractions Table 1 presents the percentage based on the mass of the main constituents of P. sapota fruit in The amount of solids in the oil samples in rela- its immature and mature states. The traditionally tion to the temperature was estimated on the basis non-edible portions accounted for about 30% of of the calorimetric results obtained according to the the total mass of the fruit; the peel was between method reported by Lambelet and Raemy (1983) 16.21 and 14.54%, the whole stone about 14%, and Menard and Sichina (2000), for which equa- and the seed inside of the stone was 10.07 and tion (1) and the program Origin 8 (OriginLab, 2007) 8.83% of the whole of the unripe and ripe fruits, were used. respectively. The average mass of mature fruits was

TABLE 1. Percentage of each constituent part of P. sapota fruit in its ripe and unripe state

Physiological state Unripe Ripe Parts of the fruit Mean ± SD (g) % Mean ± SD (g) % Total mass of the fruit 240.93±10.43 100 529.98±81.53 100 Pulp 166.50±7.05 69.10 376.04±70.16 70.95 Peel 39.06±3.62 16.21 77.10±7.75 14.54 Stone (whole) 34.86±1.94 14.46 75.86±10.06 14.31 Integument 0.0013±0.0005 0.0005 0.0041±0.0007 0.0007 Almond or kernel 24.28±1.21 10.07 46.80±9.89 8.83

slightly more than twice the weight of the imma- TABLE 2. Chemical analysis of the main parts of the ture sapotes. Mamey sapote (P. sapota) in immature and mature fruits The peel, morphologically well formed only in Stage of fruit development mature fruits, was composed mainly of crude fiber (81.32% db) and had lower contents of protein Immature Mature (6.48%), lipids (6.3%) and ash (3.89% db) (Table 2). Part/Characteristic Mean ± SDa Mean ± SDa The edible portion, the pulp, showed high mois- Peel ture contents and carbohydrates, with simple sugars Moisture NAc 44.25±0.06 in ripe fruits and polysaccharides in immature ones. Ashb NA 3.89±0.07 The results in Table 2 for the pulp portion show the effects of the biological and structural changes Oil NA 6.30±0.024 due to maturation: an increase in pH and simple Crude fiber NA 81.32±0.62 sugars at the expense of the starchy fraction; a lower Proteins NA 6.48±0.43 content of moisture, organic acids and phenolic NFEd NA 1.96±0.49 compounds (Table 2). Pulp The almond-like portion or sapote seed was Moisture 84.91±2.09 61.53±0.42 richer in lipids than the peel portion, with high values even in the earlier stage of physiological matu- pH 4.68±0.41 5.29±0.07 rity (28.31%). In mature fruits lipids represented an Ashb 6.38±0.45 3.57±0.13 average of 44.41% (db), with pieces with close to Total sugars 13.87±0.54 55.81±0.39 50% of oil having been found in the sapote seeds. Titratable acidity 0.56±0.021 0.383±0.001 This is remarkable if one takes into account that Tannins 1.66±0.16 0.037±0.002 some important traditional sources of vegetable oils have similar or lower contents: 3.5–5% in corn, NFE 77.51±0.58 40.19±0.63 18–20% in soybeans, 22–24% in cotton, and saf- Seed flower and peanuts with 25–37% and 45–50% of oil, Moisture 83.84±3.23 36.46±0.36 respectively. Other notable components in the seed Ashb 3.19±0.70 3.87±0.11 were protein and crude fiber (Table 2). Crude oil 28.31±2.07 44.41±1.66 3.3. Physicochemical properties of MSSO Crude fiber 17.71±1.22 25.69±0.53 Proteins 6.47±0.08 11.34±0.05 The purified MSSO had a refractive index of Tannins 0.16±0.01 0.177±0.006 1.463, a saponification value of 198 mg KOH/g and Cyanides 0.28±0.12 0.033±0.030 −1 an iodine value of 60 gI2·100 g of oil. NFE 43.84±0.81 14.45±2.11

3.4. Fatty acid composition of MSSO aAverage and standard deviation of three determinations; bPercent values of dry matter; cNot available; dNitrogen free extract. The seed oil composition in immature and mature mamey is shown in Table 3. This composition is relatively simple, with the main fatty acids being palmitic, respectively, for mature ones). The ratio between sat- stearic, oleic and linoleic (10.7, 26.5, 53.5 and 5.6 g urated fatty acids (SFA) monounsaturated (MUFA) of FA·100 g−1 of oil, respectively, for immature fruits and polyunsaturated ones (PUFA) was 39.9, 48.6 and 10.5, 28.6, 48.6, and 10.7 g of FA·100g−1 of oil, and 10.7, respectively, for g·100 g−1 studied in mature

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141 6 • J.A. Solís-Fuentes, R.C. Ayala-Tirado, A.D. Fernández-Suárez and M.C. Durán-de-Bazúa

TABLE 3. Chemical composition of Mamey sapote seed oil another in shoulder form at −26.2 °C. The crystal- (MSSO) extracted from immature and mature fruits lization onset temperature occurs at 4.5 °C and this Stage of fruit development process extends over a range of 41.5 °C. The crystallization enthalpy was 32 J/g. The melting curve of Immature Mature the oil solidified by rapid cooling began at −35.2 °C a a Fatty acid Mean ± SD Mean ± SD and it presented three well-defined maximum peaks Palmitic 16:0 10.79±0.035 10.50±2.63 (−2.7, 13.1 and 34.4 °C) and a small shoulder Stearic 18:0 26.57±3.96 28.65±1.82 (−31.4 °C); the process comprises a melting range of Oleic 18:1 53.59±1.87 48.62±1.95 73.2 °C with a melting enthalpy of 28.6 J/g (Table 4). Also, the thermal behavior of MSSO resembles Linoleic 18:2 5.65±0.46 10.77±0.01 that of palm oil (Tan and Che-Man, 2000); but the Linolenic 18:3 0.27±0.01 0.58±0.21 sapote oil has a broader melting range and that Arachidic 20:0 0.46±0.19 0.36±0.19 explains why this oil is liquid at ambient tempera- Behenic 22:0 0.64±0.01 0.40±04 tures in tropical regions. The calorimetric analysis N.I.b 2.03 0.3 shows the existence of three groups of acylglyceride c fractions with melting ranges at low, intermediate SFA 38.46 39.91 d and high temperatures. This enables the attainment MUFA 53.59 48.62 by fractionation of fats and oils with more specific PUFAe 5.92 11.35 thermal characteristics and phase behaviors, usable aMean and standard deviation of two determinations; bNI: not from the perspective of the extensive use of natural identified; cSFA: saturated fatty acids; dMUFA: monounsaturated vegetable fats derived without the intervention of fatty acids; ePUFA: polyunsaturated fatty acids. chemical processing and/or severe heating.

3.6. MSSO dry fractionation and thermal behavior fruits. These values are similar to those of some veg- of its fractions etable oils for industrial use such as palm oil, with the difference that, in the case of the mamey, stea- The dry fractionation of MSSO oil yielded two ric is its main saturated FA, similar to cocoa butter, solid fractions and a residual liquid fraction (RLF). one of the major industrial fats. However, in tropical The first two were obtained at 26.5 and 23.8 °C zones at room temperature, sapote seed oil is a liquid (F1 and F2, respectively) and constituted 21.0 and and not a fat, due to the presence of high levels of 19.6%, respectively, of the total oil subject to frac- oleic and linoleic acids in it. tionation. The RLF remained liquid at temperatures of 23.8 °C, representing about 59% of the processed 3.5. Thermal behavior for crystallization and melting MSSO. of MSSO Figure 2 shows the melting curves of the fractions obtained by heating them (10 °C·min−1) after Figure 1 shows the crystallization and melting their solidification by rapid cooling till −60 °C curves of MSSO. The thermal behavior in both (F1A, F2A and RLF), and the melting curves of phase changes is generally simple. The change from the samples of these solid fractions after they were liquid to solid has a well-defined peak at −2.3 °C and tempered (F1B and F2B). This last circumstance allowed for recording the effect of the polymorphism of the MSSO solid fractions. T1 The fractionation efficiency can be evaluated through the melting curves in terms of their differ- Cooling T2 ent phase behavior, that is, between the RLF and the two solid fractions; however, it is possible to notice some similarities in the curves for the solid fractions. It is known that the process of dry fractionation requires the formation of large crystals >>Exo Heating to ensure efficient separation of the fractions. Said Energy flow crystals however, forming larger clusters, trap some T1 of the remaining liquid oil or olein, which, added to T4 the conditions prevailing during the separations of T3T2 the phases, may result in fractions of “light stearin”

–60 –40 –20 0 20 40 60 80 100 or low yields of the liquid fraction (O’Brien, 1998). The melting curves in Figure 2 show that RLF Temperature, °C culminates by melting at 21 °C; the other fractions FIGURE 1. Melting and crystallization curves of MSSO. T1 to end up melting at 34.9 °C (F2A) and 39.5 °C (F1A). T4: Temperatures of phase transition. See Table 4. Molecular rearrangements favored by slow cooling

TABLE 4. Comparison of the transition temperatures during the crystallization and melting of mamey seed oil and its fractions

Transition temperatures (°C) c Curve TF-T0 (°C) T0 T1 T2 T3 T4 TF Crystallization MSSOa 41.5 4.5 −1.8 −27.4 – – −37.0 Melting MSSO 73.2 −35.2 −31.4 −2.7 14.1 34.0 38.0 RLF (A)b 43.1 −22.1 2.9 13.2 – – 21.0 F1(A) 52.0 −12.5 −1.9 9.7 27.2 – 39.5 F2(A) 45.5 −10.6 9.50 23.49 – – 34.9 F1(B) 70.8 −26.0 2.85 25.6 37.3 – 44.8 F2(B) 61.6 −12.6 −3.5 14.8 37.7 – 49.0

aMSSO: Mamey sapote seed oil (whole); bRLF(A): Residual liquid fraction crystallized by rapid cooling; F1(A): Fraction of minor melting point crystallized by rapid cooling; F2(A): Fraction of higher melting point crystallized by rapid cooling; F1(B): Fraction of minor melting point crystallized by slow cooling; c F2(B): Fraction of higher melting point crystallized by slow cooling; TF-T0: Temperature range for the transition; T0, TF: initial and final temperatures; T1, 2,3: Transition temperatures. of the fractions resulted in changes to more stable are transitions of the above forms (Hagemann, crystalline forms or polymorphs (β and β′) than α. 1988). In regard to such transitions, the molecular As it is known, lipids (fatty acids, acylglycerides, mobility, stability and their relationships are criti- and fats and oils) are meta-stable and exhibit poly- cal aspects for controlling the quality of the fatty morphism during processing and storage. Generally products that are elaborated with these materials and most commonly they solidify in three forms, the (Roos, 1995; Solís-Fuentes et al., 2005). The vast α form being the polymorph with the lowest melt- majority of phase transitions of lipids in foods, ing point (it is obtained by rapid cooling from after drugs and cosmetics associated with the behav- melting). The β′ polymorph, with a higher melting ior of processing, storage and use are established point than α, is generated under certain conditions between the solid and liquid states and the different of temperature or by a spontaneous transition from polymorphic forms of these materials (Roos, 1995; the α form. The β crystals are the most stable and Sato, 1999). Table 4 presents a comparison of the observable transition temperatures during the MSSO melting RLF(A) and its fractions. The stabilized fractions (F1B and F2B) exhibited higher end melting temperatures F1(A) than their respective non-stabilized fractions (F1A and F2A), 44.8 and 49.0 °C, and 39.5 and 34.9 °C, F2(A) respectively. F1(B) Figure 3 presents the solid-liquid relationship profiles of MSSO (measured as the percentage of

Exo>> solids) and its non-stabilized and stabilized frac- F2(B) Energy flow tions. As it is known, the ratio between the solid and liquid phases in the fat determines its consistency (i.e. hardness or firmness characteristics). These profiles include the four temperature zones in the fluency of triacylglycerols; this indirectly allows us to appreciate the lubrication properties and the pri- –60 –40 –20 0 20 40 60 80 100 mary structure of fats and oils in food products, that Temperature °C is, at refrigeration temperature (10 °C), environmental temperature (21.1 °C), body temperature (36.3– FIGURE 2. Melting curves residual liquid fraction and solid fractions obtained from MSSO with different thermal history. 37.8 °C) and of the preparation of fatty products RLF(A): Residual liquid fraction crystallized by rapid cooling; (40 °C) (O’Brien, 1998). F1(A): Fraction of minor melting point crystallized by rapid According to its phase behavior, as shown in cooling; F2(A): Fractión of higher melting point crystallized Fig. 3, the mamey seed contains an oil with the char- by rapid cooling; F1(B): Fraction of minor melting point crystallized by slow cooling; F2(B): Fraction of higher acteristics of a liquid fat because at 20 °C it has 6% melting point crystallized by slow cooling. solids; at 10 °C 25% and at 0 °C almost 50%.

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141 8 • J.A. Solís-Fuentes, R.C. Ayala-Tirado, A.D. Fernández-Suárez and M.C. Durán-de-Bazúa

100 100

80 80 (C) (B) (A) (D) 60 60 F1(B) F1(A) MSSO F2(A)

Solids, % 40

Solids, % 40 F2(B) 20 20

0 0 02040 0204060 Temperature °C Temperature, °C FIGURE 4. Profile of solid of mixtures of MSSO and its FIGURE 3. Profile of solid Fat of MSSO and solid fractions solid fraction (F2) with mango and cocoa fats. A) 75:25 MSSO- separated at 23.8 and 26.5 °C. MSSO: Mamey sapote seed oil; Mango seed fat; B) Cocoa butter; C) 25:75 MSSO(F2)-Cocoa F1(A): Fraction of minor melting point crystallized by rapid butter; D) 25:75 MSSO(F2)-Mango seed fat. cooling; F2(A): Fractión of higher melting point crystallized by rapid cooling; F1(B): Fraction of minor melting point crystallized by slow cooling; F2(B): Fraction of higher melting point crystallized by slow cooling. fraction (F2A), with 75% of CB in one case and 75% of mango seed fat (MSF) in the other, respectively. In both cases, a great similarity in the solids Except for MSSO (and RLF, which is not pre- profile to that of the fat model CB is evident. In the sented in Fig. 3) which has a solid profile that gives first case, the approximation to the CB curve is very the oil a liquid consistency at ambient temperatures close, and represents the possibility of partial sub- in tropical regions (20–22 °C), all fractions showed stitution with this fraction of MSSO in products solid consistency with a solid index >35%, which that use CB as the fat ingredient. In the second case means that over a third of their acylglycerides in the (curve D), it is shown that the mixture of two non- solid-crystalline phase are suspended in less than conventional natural fats such as MSF and the solid two-thirds of liquid triglycerides at that tempera- fraction of MSSO have a phase behavior close to ture. This solid/liquid ratio decreases differently in that of CB. these fats as the temperature rises and is minimized for all at around 40 °C (Fig. 3). 4. CONCLUSIONS The stabilized samples, with polymorphic effects, showed important shifts in their solid profiles P. sapota is a multi-purpose plant endemic to towards higher temperatures. Mesoamerica and has been used since prehispanic The solid fractions of MSSO showed different times. Its fruit, prized for the characteristics of its degrees of plasticity than those required for the man- flesh, has been used for domestic and artisanal pur- ufacture of confectionery products, bakery shorten- poses in the different cultures of America. Mamey ings and frying fats. sapote consumption generates waste of great poten- Figure 4 shows the solid profiles of blends of tial as a source of raw materials for the production MSSO and its F2 solid fraction, with better known of different products that are currently being scien- fats, such as cocoa butter (Theobroma cacao L., with tifically, technically and economically evaluated. a broad spectrum of industrial applications in the According to the results of this work, mameys fields of food, pharmaceuticals and cosmetics), and contain about 30% of waste portions. In mature and mango seed fat (Mangifera indica, L., widely inves- immature fruit, the peel represents about 16% and tigated in recent years; Solís-Fuentes and Durán the stone about 14% of the fruit. The kernel of the Bazúa, 2004; Jahurul et al., 2014). stone or seed is of great interest mainly for its lipid Curve B shows the solids profile of tempered and protein composition. The seed has a high con- cocoa butter (CB) with its characteristic deep slope, tent of oil even in its earlier stages of physiological a rapid decrease the percentage of solids at around maturity. This oil has been appreciated and used in human body temperature. This property is highly the producing regions in traditional medicine and appreciated in the vast number of applications of cosmetic applications, but currently its commercial this fat. use is still incipient. In MSSO the oleic, stearic, pal- Curves C and D correspond to tempered mix- mitic and linoleic fatty acids are predominant, as tures whose weight contains 25% of the MSSO solid occurs in many vegetable fats and oils from various

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141 Mamey sapote seed oil (Pouteria sapota). Potential, composition, fractionation and thermal behavior • 9 origins, and, are widely used in the food industry. Krasuk JH, Lombardi JL, Ostrovsky CD. 1967. Difusión extac- tion of oil containing materials. Proc. Des. Dev. 6, 187–195. The thermal and phase behavior of this oil is rel- http://dx.doi.org/10.1021/i260022a006. atively simple, with a broad melting range (73 °C) Lambelet P, Raemy A. 1983. Isosolid diagrams of fat from and three maximum melting temperature peaks at thermal analysis data. J. Am Oil Chem. Soc. 60, 845–847. −2.7, 13.1 and 34.4 °C. http://dx.doi.org/10.1007/BF02787442. Laiz-Saldaña JC, Tovar-Miranda R, Durán-de-Bazúa MC, The dry fractionation of MSSO allowed for its Solís-Fuentes JA. 2009. Aprovechamiento de residuos separation into three fractions, two solid and one agroindustriales: Producción de biodiesel por tranesteri- liquid at room temperature (about 22 °C). The solid ficación alcalina de aceite crudo de almendras de zapote mamey (Pouteria sapota) Tecnol. Ciencia Ed. (IMIQ). 24, fractions, with different thermal and phase behavior 48–56. and solid-liquid relationships, had the physical char- Mehlenbacher VC. 1960. Análisis de Grasas y Aceites, acteristic of natural vegetable fats. Enciclopedia de la Química Industrial, Tomo 6, Ediciones Once stabilized, the obtained solid fractions Urmo. España. Pág. 330–344. Menard KF, Sichina WJ. 2000. Prediction of solid fat index (SFI) showed significant shifts in their solid percentage values of food fats using DSC. Perkin Elmer Application toward higher melting temperatures as an effect of Note, p. 1–3. the polymorphic transitions. Morera JA. 1994. Sapote (Pouteria sapota). In Neglected Crops:1492 from a Different Perspective. JE Hernándo- Mixtures of the solid fractions of MSSO with Bermejo and J León (Eds.) Plant Production and Protection other natural fats, such as CB and MSF, showed Series 26. Rome, Italy. 103–109. their potential as fatty constituent in the design of Morton J. 1987. Sapote. In Fruits of Warm Climates. JF Morton, Miami, FL. EEUU. substitutes or equivalents for fats of industrial inter- Nava-Cruz Y, Ricker M. 2004. El Zapote Mamey (Pouteria est such as CB. sapota (Jacq) H. Moore y Stearn), un fruto de la selva mex- icana con alto valor comercial. En Productos Forestales, Medios de Subsistencia y Conservación, Vol. 3 América ACKNOWLEDGEMENTS Latina. Alexiades MN, Shanley P (Ed.). CIFI. Bogor Barat, Indonesia. The authors wish to thank the Institute of O’Brien R. 1998. Fats and Oils. Technomic Pub. Co. Lancaster, Materials Research of the UNAM for its support to Penn. EEUU. OriginLab. 2007. Origin Pro 8 SRO. OriginLab Corporation. the realization of the calorimetric analysis included Northampton, MA, USA. in this work. Parodi Nutra. 2013. Dossier scientifique sur l’huile de sapote pour un usage en cosmetique. Rapport d’etude Parodi Nutra CPO 0606013. REFERENCES Precht D, Molkentin J. 1995. Trans fatty acids: implications for health, anlytical methods, incidence in edible fats and Álvarez-Reyes AR, Solís-Fuentes JA, Durán-de-Bazúa MC. 2001. intake. Food Nahrung 39, 343–374. Coeficientes de difusividad aparente durante la extracción Roos YH. 1995. Phase Transitions in Foods. Academic Press. de aceite de almendras de zapote mamey (Pouteria sapota). Londres, Inglaterra. Tecnol. Ciencia Ed. IMIQ. 16, 20–27. Sato K. 1999. Solidification and phase transformation behavior Bannon CD, Craske JD, Hai NT, Harper NL, O’Rourke K. 1982. of food fats, a review. Lipid-Fett. 101, 467–474. http://dx.doi. Analysis of fatty acid methyl esters with high accuracy and org/10.1002/(SICI)1521-4133(199912)101:12<467::AID- reliability II. Methylation of fats and oils with boron tri- LIPI467>3.0.CO;2-D. fluoride-methanol. J. Chrom. A, 247, 63–69. http://dx.doi. Simeón R. 2002. Diccionario de la Lengua Náhuatl o Mexicano. org/10.1016/S0021-9673(00)84856-6. Siglo XXI. México, DF. México. Cravotto G, Binello A, Orio L. 2011. Green extraction tech- Silva CAM, Simeoni LA, Silveira D. 2009. Genus Pouteria: niques for high-quality natural products. Agro-Food Chemistry and biological activity. Brazilian J. Pharmacognosy Industry Hi-Tech 22, 57–59. 19, 501–509. De la Llata-Romero L. 2013. Method of obtaining total fixed Solís-Fuentes JA, Tapia-Santos M, Durán-de-Bazúa MC. lipids from seeds of the sapotaceae family, for the prepara- 2001. Aceite de almendra de zapote mamey, un análisis tion of cosmetics and dermatological pharmaceutical com- de rendimientos y condiciones de extracción. Información positions. USA Patent 545900 B2. Tecnológica. 12, 23–28. Hagemann JW. 1988. Thermal behavior and polymorphism of Solís-Fuentes JA, Durán-de-Bazúa MC. 2002. Indigenous acylglycerides. En Garti, N, Sato K (Eds.) Cristallization Species Appropriate Use, a Support Towards Sustainability: and Polimorphism of Fats and Fatty Acids, vol. 31. Marcel Zapote Mamey (Pouteria sapota) in Mesoamerica. En, Li Dekker. NY, USA. Dajue (Ed.) Proceedings of Second International Conference Hendrikse PW, Harwood JL, Kates M. 1994. Analytical methods. on Sustainable Agriculture for Food, Energy and Industry. En The Lipids Handbook, Gunstone FD, Hornwood JL Chinese Academy of Science. Beijing, China. (Eds.) Chapman and Hall Chemical Database. NY, USA. Solís-Fuentes JA, Durán-de-Bazúa MC. 2004. Mango seed Horwitzs W. 1995. Official Methods of Analysis of the uses: Thermal behaviour of mango seed almond fat and its Association of Official Analytical Chemist. AOAC mixtures with cocoa butter. Bioresour. Technol. 92, 71–78. Washington DC, USA. http://dx.doi.org/10.1016/j.biortech.2003.07.003. Jahurul MHA, Zaidul ISM, Norulaini NAN, Sahena F, Abedin Solís-Fuentes JA, Hernández-Medel MR, Durán-de-Bazúa MZ, Ghafoor K, Mohd Omar AK. 2014. Characterization MC. 2005. Determination of predominant polymorphic of crystallization and melting profiles of blends of mango form of mango (Mangifera indica) almond fat by differ- seed fat and palm oil mid-fraction as cocoa butter replacers ential scanning calorimetry and X-ray diffraction. Eur. J. using differential scanning calorimetry and pulse nuclear Lipid Sci. Technol. 107, 395–401. http://dx.doi.org/10.1002/ magnetic resonance. Food Research International. 55, 103– ejlt.200401072. 109. http://dx.doi.org/10.1016/j.foodres.2013.10.050 Tan CP, Che-Man YB. 2000. Differential scanning calorimetric Khosla P, Sundram K. 1996. Effects of dietary fatty acid com- analysis of edible oils: Comparison of thermal properties position on plasma cholesterol. Prog Lipid Res. 35, 93–132. and chemical composition. J. Am. Oil Chem. Soc. 77, 143– http://dx.doi.org/10.1016/0163-7827(95)00014-3. 155. http://dx.doi.org/10.1007/s11746-000-0024-6

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141 10 • J.A. Solís-Fuentes, R.C. Ayala-Tirado, A.D. Fernández-Suárez and M.C. Durán-de-Bazúa

Tarrago-Trani MT, Phillips KM, Lemar LE, Holden JM. 2006. Timms RE. 2006. Fractionation of palm oil: Current status, New and existing oils and fats used in products with future possibilities. En Timothy L. Mounts Award Address reduced trans fatty acid content. J. Am. Dietetic Assoc. 106, presented at the AOCS World Conference and Exhibition on 867–880. http://dx.doi.org/10.1016/j.jada.2006.03.010. Oilseed and Vegetable Oil Utilization. Timms RE. 1985. Physical properties of oils and mixtures of Triono T, Brown AHD, West JG, Crisp MD. 2007. A phylogeny oils. J. Am. Oil Chem. Soc. 62, 241–249. http://dx.doi. of Pouteria (Sapotaceae) from Malesia and Australasia. org/10.1007/BF02541385. Aust. Syst. Bot. 20, 107–118. http://dx.doi.org/10.1071/ Timms RE. 2005. Fractional crystallization–the fat modification SB06011. process for the 21st century. Eur. J. Lipid Sci. Technol. 107, 48–57. http://dx.doi.org/10.1002/ejlt.200401075.

Grasas Aceites 66 (1), January–March 2015, e056. ISSN-L: 0017–3495 doi: http://dx.doi.org/10.3989/gya.0691141